Friction-spring.



R. D. GALLAGHER, IR. FRICTION SPRING.

APPLICATION FILED NOV. 6. IBM.

Patented July 20, 1.915.

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willineooeo H. D. GALLAGHER, JR. FRICTION SPRING.

APPLICATION FILED NOV- 5. 1914.

Patented July 20, 1915.

9 9 2 suns-sun 2 E I55 EI 16 6 Elwuwwtoz RICHARD D. GALLAGHER JR, OF NEW YORK}, N. Y.

FRICTION-SPRING.

LILMRFSS.

Specification of Letters Patent. Pafi gnt d J l q) 1915 I Application filed November 6, 1914. Serial No. 870,666.

To all whom it may concern:

Be it known that I, RICHARD D. GALLA- GHER, Jr., a citizen of the United States, re-

siding at New York, in the county and State of New York, have invented certain new and useful Improvements in Friction-Springs; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specifica f tion, and to the figures and-letters of reference marked thereon.

This invention relates to improvements in springs, and more particularly to friction springs of the type which include inner and outer friction coils having faces adapted to frictionally engage each other upon compression ofthe spring.

In springs of the type referredto, it is well known that there is a tendency for one sequently breaking, or bending of the coils frequently occurs.

One object of the present invention is to so construct the caps 01' followers at each end of the spring that they will positively prevent creeping of one coil relative to the other, this being preferably effective by the provision of means operatively associated with each cap and adapted to engage the coils and prevent creeping thereof.

Another object of the invention is to so arrange the caps at the ends of the springs that while permitting them free longitudinal movement substantially in the direction of the longitudinal axis of the spring, they are positively held against rotation with relation to each other and to the spring.

A full understanding of the invention will be-obtained from the following detailed description, taken in connectionnwith the ac companying drawings illustrating a construction embodying the same in a preferred form. t

In the drawings Figure L is anelevation of the improved friction spring; Fig. 2 is a section on the line 22 of Fig. 1; Fig. 3 -;.1s a section on the line 38 of Fig. 2 with the spring and connecting rivet omitted; Fig. 4t 1s a section on the line 4-f of Fig. 2; Fig. 5 is an elevation of a modified form of spring; Fig. 6 is a section on the line 6+6 of Fig. 5; Fig. 7 is a longitudinal sectional'section showing one method of applyingthe form of spring illustrated in Fig. 5; and Fig. 8 is a plan view of the arrangement shown in Fig. 7, on a reduced scale.

Referring in detail to thedrawings, wherein similar characters of reference rep resent similar parts throughout the several views, the spring is made up of a plurality of concentric coils, these consisting of a central coil 1, preferably in the form of an ordinary helical spring, the inner friction coil 2, and the outer friction coil 3. The inner and outer friction coils 2 and 3 are provided with opposed friction faces 4 and 5 which frictionally engage each other upon compression of the spring. The central coil 1 serves to supplement the action of the two friction coils and is provided with squared or flattened ends 6 which rest against the caps or followers 7 and 8, respectively.

The primary object sought to be attained by the present invention is to positively pre vent creeping of one friction coil with rela tion to the other. This is accomplished by arranging the caps in such manner that while they are permitted to move longitudinally of the axis of the springs, relative rotary movement is prevented; and by providing each cap with a stop adapted to contact with the friction coils 2 and 3 and positively prevent creeping thereof with relation to each other. For this purpose, the cap 7 is provided with an abutment 9, and the cap 8 with an abutment 10. In the preferred construction, the caps are duplicates but are mounted in reversed position at'the ends of the springs. The abutments 9 and 10 are formed on the inner faces of the caps, their tendency toward creeping or rotarty movement of the coils occur. As shown in Fig. 3, the abutments 9 and 10 taper from their end faces at an angle which conforms substantially to the inclination of the friction coils from the horizontal, or to the plane of the caps. The tapering abutments are furthermore shaped with inclined faces to re ceive the coils of the inner and outer friction springs and have one portion of such face, for example 10, engaging the inner is very advantageous, in that buckling of the springs is'prevented and it is not necessary to taper the ends of the coils down to an.

edge. As shown, the outer coil 3 is not tapered at all, and the inner coil only slightly tapered. By modifying the shape of the abutment, it will be found easy to eliminate tapering of both coils.

The caps at each end of the spring are mounted thereon in such manner that while they are permitted a relative sliding movement substantially in the direction of the longitudinal axis of the spring, rotation of the caps on the ends of the springs is prevented. In the vform of the invention illustrated in Figs. 1 to 4, inclusive, cap 7 is provided with a sectional or semi-cylindrical spindle 11 adapted to project within the central-coil 1 of the spring, and cap 8 with a similar spindle 12, these spindles 11 and 12 being'a-rranged on opposite sides of their respective caps. Each spindle is provided with a lug or shelf 13,14. These lugs eX- tend transversely of the longitudinal axis of the spring and are substantially in alinement with said axis when the caps are mounted on the opposite ends of the spring. When the caps are so mounted the spindles face each other, and are connected preferably by a pin or rivet 15 extending through apertures in the alined lugs 13, 14. The rivet or bolt 15 so connects the opposed spindles that whilethey are'permitted to slide relatively to each other when compression is applied to the spring, rotary movement is positively prevented by the engagement of the edges of the semi-cylindrical spindles and hence the caps 7 and 8 at the ends'of the spring are held against relative rotary movement. The combined fixed relation of the caps against rotary movement and the abutments against which the ends of the friction coils are adapted to engage efl'ectually prevents creeping of the coils.

The improved spring has an exceedingly small number of parts which may be standardized permitting substitution of new parts in the event of breakage. It will also be noted that the anti-creeping feature insures a-much more efficient and longer life to the spring, by practically obviating the objectionable creeping of the coils.

In the form of the invention illustrated in Figs. 5 to 7 inclusive, the caps 16 and 17 are fixed against rotary movement by the manner of connection to the draft or other device with which the spring is adapted to be used. As shown the caps are substantially square and work between parallel guides 20 which guides may be parts of a draft rigging. It is obvious, however, that the shape of the caps is immaterial for any non-circular shape will prevent rotary movement, and it is accordingly to be understood that the invention is not limited to the exact forms shown.

While I have shown and described a certain structural modification of my invention, it will be understood that the same is i not to be limited thereto, but on the contrary is capable of considerable modification and variation Within the scope of the claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is,

1. In a-friction spring, the combination of'outer and inner coils having cooperating friction faces, and a spring cap provided with an abutment adapted to be engaged by each of said coils to prevent creeping of the coils with relation to each other.

2-. In a spring. the combination of outer and inner spring coils, a spring cap, and means associated with said cap and cooperating with both coils for preventing creeping of each of said coils With relation to the other.

3. In a friction spring, the combination of outer and inner coils having cooperating friction faces, a spring cap at each end of the spring, and means associated with said caps for preventing creeping of each of said coils with relation to the other.

i. In a friction spring, the combination of.

outer and innercoils having coiiperating friction faces, and spring caps, one at each end of the spring, means for holding the caps against rotation with relation to each other, and means for preventing creeping of said coils, with relation to each other.

5. In a friction spring, the combination of inner and outer friction coils, a cap at each end of the spring, means for preventing rotation of the caps with relation toeach other, and means for preventing creeping of the spring coils.

6. In a friction spring, the combination of inner and outer spring coils, a cap at each end of the spring, said caps having cooperating slidable spindles extending within the spring, and a rivet connecting the spindles and arranged to permit them to slide relatively to each other, While preventing relative rotary movement of the caps.

7 In a spring, the combination With inner and outer friction coils, of a cap at each end of the spring, and abutments carried by the cap having substantially vertical faces adapted to be engaged by the ends of said 

